1. Field of the Invention
The present invention relates to flaring tools used to produce an outwardly flared edge on the outer conductor of a coaxial cable.
2. Description of Related Art
Coaxial cables include an inner conductor and a concentric outer conductor separated by an insulating dielectric material. The outer conductor of certain types of coaxial cables intended for high frequency applications is made of a solid, but thin, sheet of conductive material, such as copper or aluminum, which has the approximate shape of a thin-walled cylindrical pipe or tube. In order to permit the cable to be stored on a roll or routed around corners, the outer conductor may be annularly corrugated, which allows the cable to flex. In large diameter coaxial cables of this type, the inner conductor is hollow and tubular in shape.
In order to make a connection to a cable of the type described, a connector is placed over the end of the coaxial cable and the solid outer conductor is flared outward into contact with an inner surface of the connector. Flaring tools that are presently available to perform this function include a handle, an element that engages the center conductor, so that the tool may be rotated around the axis of the cable, and a conical flaring head that contacts the inner edge of the outer conductor and presses it outward to form the flare as the tool is rotated.
The element that engages the center conductor of larger diameter cables with hollow inner conductors is typically an outwardly extending shaft having an outside diameter corresponding to the inside diameter of the hollow inner conductor. The shaft is inserted into the hollow inner conductor in axial alignment with the cable and the tool is then pressed axially against the end of the cable. This brings the conical flaring head to the junction between the inner surface of the outer conductor and the outer surface of the insulating dielectric. The tool is then rotated around the axis of the cable and the conical flaring head presses the outer edge of the outer conductor outward to form the flare.
Prior art tools of the type described are typically suitable for only a single diameter cable. This requires the workman to carry one tool for each different diameter of cable that may need to be flared.
Another difficulty with prior art tools is that the conical flaring head produces an undesirable inward flare on the outer surface of the insulating dielectric material at the same time as the desired outward flare is produced on the outer conductor. This inward deformation of the dielectric insulator can produce signal distortions in high frequency cables.
Prior art flaring tools of the type described have typically used a relatively narrow and long handle, similar to a screwdriver handle. Such tools can be awkward to use and it is difficult for the workman to apply sufficient rotational torque to produce a flare on the largest diameter cables.
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide a flaring tool that can flare more than one diameter of cable.
It is another object of the present invention to provide a flaring tool that does not distort the insulating dielectric material.
A further object of the invention is to provide a flaring tool that is compact, comfortable to use and allows the user to produce a high level of axially applied force while simultaneously producing a high rotational torque as required to flare large diameter coaxial cables.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.